21202018 has 16 divisors (see below), whose sum is σ = 32366880. Its totient is φ = 10414656.

The previous prime is 21202003. The next prime is 21202033. The reversal of 21202018 is 81020212.

It is an interprime number because it is at equal distance from previous prime (21202003) and next prime (21202033).

It is a junction number, because it is equal to n+sod(n) for n = 21201992 and 21202010.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55753 + ... + 56131.

It is an arithmetic number, because the mean of its divisors is an integer number (2022930).

Almost surely, 2^21202018 is an apocalyptic number.

21202018 is a deficient number, since it is larger than the sum of its proper divisors (11164862).

21202018 is a wasteful number, since it uses less digits than its factorization.

21202018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 21202018 is about 4604.5649088703. The cubic root of 21202018 is about 276.7742820978.

The spelling of 21202018 in words is "twenty-one million, two hundred two thousand, eighteen".